DESCRIPTION (Adapted from the application) The overall objectives of the core are to provide facilities and expertise to researchers for in vivo characterization of normal and pathophysiological mechanisms of hormonal and neural regulation of GI function and brain gut interactions. They provide the investigators with 1. In vivo experimental models to assess gastric, pancreatic, and intestinal function in rats, mice, and other species; 2. Specialized facilities and equipment for measuring GI secretory, motor, and nerve functions; 3. Methods for in vivo administration of peptides, neurotransmitters, and drugs, sampling blood and body fluids, and removing tissues; 4. Methods to assess afferent and efferent arms of the pathways in brain-gut interactions; and 5. Expertise in protocol design and data interpretation for in vivo studies.